Why can't Mac Pro 1.1s use newer video cards?

[ADDvanced]

I'm looking to upgrade my machine's GPU, but many video cards say only 3.1, 4.1 or 5.1 mac pros or later. What is preventing my machine from using these cards?

I have already installed El Capitan and modded the EFI, it works great. Thanks!

 

[cw48494]

If you're running the Tiamo or Pike R. Alpha boot.efi that allows these machines to run 10.8 or later, you're fine using any of those cards.

 

[SDAVE]

It's also PCIe 1.1 I think, which is really old. Almost 10 years.

 

[Fl0r!an]

Your MacPro can't take use of flashed EFI64 cards (e.g. any Nvidia card from the last years), so you won't see a boot screen with those. This will not change when you modify your boot.efi, 2 completely different things!

Besides that the supported GPUs are only determinded by the installed OS, so of you run Yosemite or El Capitan you can use the same cards as a newer MP running the same OS.

The most recent flashable cards are Radeon HD 7xxx/R9 cards (check other threads). Obviously they'll be bottlenecked in games by your 10yo hardware.

 

[ActionableMango]

It will work after booting. The reason why people said it won't meet your needs in your other thread is because in the other thread you said you needed boot screens, which you aren't mentioning in this thread.

 

[SDAVE]

Slap in a used GT120 if u need bootscreen, OP.